CN108694961A - Digitized audio frequency - Google Patents
Digitized audio frequency Download PDFInfo
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- CN108694961A CN108694961A CN201810283497.0A CN201810283497A CN108694961A CN 108694961 A CN108694961 A CN 108694961A CN 201810283497 A CN201810283497 A CN 201810283497A CN 108694961 A CN108694961 A CN 108694961A
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- recording medium
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
- G11B5/09—Digital recording
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/02—Analogue recording or reproducing
- G11B20/04—Direct recording or reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10037—A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10222—Improvement or modification of read or write signals clock-related aspects, e.g. phase or frequency adjustment or bit synchronisation
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10305—Improvement or modification of read or write signals signal quality assessment
- G11B20/10398—Improvement or modification of read or write signals signal quality assessment jitter, timing deviations or phase and frequency errors
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10527—Audio or video recording; Data buffering arrangements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/22—Signal processing not specific to the method of recording or reproducing; Circuits therefor for reducing distortions
- G11B20/225—Signal processing not specific to the method of recording or reproducing; Circuits therefor for reducing distortions for reducing wow or flutter
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/02—Editing, e.g. varying the order of information signals recorded on, or reproduced from, record carriers
- G11B27/031—Electronic editing of digitised analogue information signals, e.g. audio or video signals
- G11B27/032—Electronic editing of digitised analogue information signals, e.g. audio or video signals on tapes
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/36—Monitoring, i.e. supervising the progress of recording or reproducing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/222—Studio circuitry; Studio devices; Studio equipment
- H04N5/253—Picture signal generating by scanning motion picture films or slide opaques, e.g. for telecine
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B2220/00—Record carriers by type
- G11B2220/90—Tape-like record carriers
- G11B2220/91—Helical scan format, wherein tracks are slightly tilted with respect to tape direction, e.g. VHS, DAT, DVC, AIT or exabyte
- G11B2220/913—Digital audio tape [DAT] format
Abstract
The invention discloses a kind of methods for digitizing the track being carried in strip recording medium (e.g., cinefilm).The method, including:Recording medium containing track is conveyed through reader, its sequence is made to read track, analog output signal is generated by reading track;The method further includes:It senses the transmission rate of the recording medium and analog output signal is sampled with the sample rate determined based on the transmission rate sensed so that analog output signal digitizes.The present invention further discloses a kind of digitized audio frequency systems.
Description
Technical field
The present invention relates to digitized audio frequency system and methods.
Background technology
Sound is recordable on audiotape, tape, film, digital audio tape (DAT), CD or other SoundRec media.
Sound can be stored as analog signal or digital signal according to the Recording Process of actual use and the recording medium used.Past leads to
Often it is recorded to audio as time sequencing analog signal in open reel tape, film or other strip recording mediums.This record
Sound is commonly referred to as " track ".Recording medium may include multiple tracks to store different recording channels.
Simulated sound can be converted into digital audio, and vice versa.Analog sound information is converted into digital sound information
Process be commonly known as digitized audio frequency.The system for executing digitized audio frequency processing can be independent system, can also incite somebody to action
It is attached to glue and turns in the multimedia processing systems such as magnetomechanical or film scanner.In order to which film or cassette record will be recorded in
Track in the strips recording mediums such as band is converted into digital form, and digitized audio frequency system is usually required containing transmission mechanism,
Reading head is continuously passed through for transmitting strip recording medium.(but uncommon) on the contrary, medium can remains stationary, and reading head
Mobile or reading head and medium both move.Reading head reads the analog sound information of storage, then generates table in turn
Show the simulation output of simulated sound.Then, before being again stored in digital form in simulation output in suitable recording medium,
The simulation output is sampled with presetting sample rate by analog-digital converter.
In these cases, reading head is continuously passed through since SoundRec medium need to be transmitted via physics, transmission system
The stability and accuracy of system are to ensuring that the quality of digital audio plays an important role.The mechanical performance of Transmission system needs steady
It is fixed, accurate, to ensure that digital voice signal will not be damaged because of transmission speed difference.However, can not usually avoid completely by
Tape or the irregular of film rotate caused digitized voice defect.For example, " flutter " is exactly to become for describing pitch
The term of change, change in pitch therein be during speech simulation reappears due to the irregular rotation of film or tape in number
It is captured in change audio signal.
Existing several solutions can be used for improving the Transmission system of digital audio system, make sound because of tape or adhesive tape
The caused defect of irregular rotation, which reaches, to be minimized.One of which solution is related to digitized audio frequency system being placed on machine
On tool performance stabilised platform, make transmission process that can be carried out without any interference.Another solution is related to profit
Gradually weaken the variation of actuating speed with high-precision bearing and heavy flywheel.Although can get sometimes using this Transmission system
Preferable sound quality, but it is expensive, and it is very heavy.
Therefore, it is proposed to which another solution, is located by a series of " smoothing " steps in computer software
Digitalized audio record is managed, to detect and remove abnormal change in pitch.Celemony software packages are exactly one of them.However, based on soft
The solution of part is considered expensive, and other steps are also introduced in digitized audio frequency workflow.
It solves at least one defect in the prior art accordingly, it is desirable to provide one kind is improved or at least can be used as the public
An alternative selection digitized audio frequency system and method.
The reference of any prior art is not to recognize that or is implied in this specification the prior art in any judicial pipe
Constituting a part for common knowledge or the prior art in linchpin power can be appreciated by those skilled in the art by rational expectation, regard
For correlation and/or combine its any part.
Invention content
In generalized concept, the present invention is based on a kind of understanding of inventor, i.e., when seeking analog signal digital, can lead to
The whole digitized process of toning corrects transmission speed deviation, to making up this deviation, wherein analog signal is using generating mould
The signal that the reader of quasi- signal is read relative to the method that the track of coding simulation audio translates from recording medium.In spy
In other preferred embodiment, in the case where requiring to sample analog audio signal with target sampling rate, actual sample rate can be with
It is different from target sampling rate, to compensate transmission speed deviation.In order to reflect deviation that reader is subjected to, it is preferable that
Reader or determining relative transport speed (or relative transport velocity deviation) near it.Accordingly, in a preferred embodiment, relatively flat
The positive variation rate (increase) of speed is moved so that actual sample rate accordingly increases, and the negative variability (reduction) of relative translation speed is so that real
Border sample rate accordingly reduces.
In the first aspect, a kind of method for digitizing the track being carried in strip recording medium is disclosed,
This method, including:
Recording medium containing track is conveyed through reader, its sequence is made to read track;
The track is read by reader, to generate analog output signal;
Sense the transmission rate of recording medium;And
Analog output signal is sampled with the sample rate determined based on the transmission rate sensed so that analog output signal
Digitlization.
Sample rate can be determined based on the modulator clock signal with clock modulation frequency.
In the second aspect, a kind of method for digitizing the track being carried in strip recording medium is disclosed,
This method, including:
Recording medium containing track is conveyed through reader, its sequence is made to read track;
The track is read by reader, to generate analog output signal;
Sense the transmission rate of recording medium;
The modulator clock signal with clock modulation frequency is generated based on the transmission rate sensed;And
Modulator clock signal is applied to analog-digital converter so that analog output signal digitizes.
In the embodiment of above-mentioned aspect, the step of transmission rate for sensing recording medium, may include:
Determine the rotational frequency or speed of at least one rotary part of the transmission mechanism of bearing recording medium.
In one embodiment, the step of transmission rate for sensing recording medium, may include any one in following steps
Or it is multiple:
Monitor the rotation of at least one rotary part of the transmission mechanism of bearing recording medium;
Monitor the rotating element for being rotationally attached at least one rotary part of transmission mechanism;And
Monitor the linear movement of the element moved by least one rotary part.
In one embodiment, the step of transmission rate for sensing recording medium, may include:
One or more output signals are received from the encoder for the rotary part for being rotationally attached to transmission mechanism.
This method may include:Clock modulation frequency is adjusted based on the output signal received from encoder.
In one embodiment, clock modulation frequency is determined based on adjustment frequency and clock base frequency.
In one embodiment, the rotary part each rotation of transmission mechanism, encoder generate 512 output signals.
In one embodiment, clock base frequency can be 12.288MHz.
In one embodiment, target sampling rate is about 48kHz.
In one embodiment, the rotary part synchronous rotary of encoder and transmission mechanism.
In one embodiment, the rotary part of transmission mechanism may include roller, gear, sprocket wheel, driving wheel, mandrel, axis and
It is any one or more in spool etc..
Most preferably, rotary part is to rotate consistent high precision roller with recording medium.
In one embodiment, the step of reading track may include one or more of following steps:
Receive the optical signal for indicating pumped FIR laser track;Or
Sense magnetic encoded tracks.
In one embodiment, this method further includes:
Digitized simulation output signal is transmitted to buffer storage;
Monitor the state of buffer storage;And
State based on buffer storage adjusts clock modulation frequency.
In one embodiment, this method further includes:
Based on one or more of following reference frequency for determining digitized simulation output signal:
The measurement speed or speed of at least one rotary part of the transmission mechanism of bearing recording medium;And
The input signal that at least one rotary part of driving transmission mechanism rotates.
Reference frequency can be associated with the final output code check of Digital output signal.
In one embodiment, this method further includes:
Access the digitized simulation output signal being stored in buffer memory;And
Based on reference signal and the digitized simulation output signal being stored in buffer storage, the digitlization of correction is generated
Analog output signal.
In terms of third, a kind of digitized audio frequency system is disclosed, the digitized audio frequency system, including:
Reader is configured to read from the audio-frequency information of storage on the recording medium, and generates analog output signal;
Transmission mechanism is configured to the recording medium for making carrying need digitized audio-frequency information and passes through reader;And
Analog-digital converter is configured to sample the analog output signal of reader with sample rate, wherein sample rate depends on
The transmission rate of recording medium.
Preferably, transmission mechanism, including:Sensing system is arranged to sense the transmission rate of recording medium.
The sensing system, which can be configured to output, can be directly used as the reference clock signal of clock signal, or be believed by clock
Number generator generates the clock signal used for analog-digital converter.
In the first aspect, a kind of digitized audio frequency system is disclosed, the digitized audio frequency system, including:
Reader is configured to read from the audio-frequency information of storage on the recording medium, and generates analog output signal;
Transmission mechanism is configured to the recording medium for making carrying need digitized audio-frequency information and passes through reader;And
Clock signal generators are configured to generate modulator clock signal;And
Analog-digital converter (ADC) is configured to sample the analog output signal of reader based on modulator clock signal.
Preferably, Transmission system, including:Sensing system is arranged to sense the transmission rate of recording medium.
In the above-described embodiments, sensing system is in the transmission rate for sensing recording medium adjacent to the position of reader.
Transmission sensing system may include the encoder for the component for being rotationally attached to transmission mechanism, wherein the conveyer
The component of structure passes through reader synchronous rotary with transmission recording medium.
Encoder can be connected to any one or more in roller, gear, sprocket wheel, driving wheel, mandrel, axis and spool etc.;
Rotating element is rotationally attached among the above any one.
Reader may include it is following in it is any one or more:
Optical pickup is configured to read from pumped FIR laser track;Or
Magnetic reader is configured to read from magnetic encoded tracks.
Digitized audio frequency system can be the composition portion that glue turns magnetomechanical, cinefilm scanner and video digitizer etc.
Point.
In addition to requiring otherwise herein, word " including (comprise) " used herein and its variant is (e.g.,
" comprising ", " comprises " and " comprised ") it is not intended to exclude other additives, component, integer or step.
Be described below by way of example combination attached drawing, other aspects of the present invention and it is each section above-mentioned described in
The other embodiment of aspect will become obvious.
Description of the drawings
Fig. 1 is the schematic diagram according to the digitized audio frequency system of one embodiment.
Fig. 2 is cinefilm diagram, shows the position of the analog sound track in one embodiment.
Fig. 3 is the schematic diagram of the other details of the frequency digitization system of sound type shown in Fig. 1.
Fig. 4 is the schematic diagram of the additional detail of the digitized audio frequency system of type shown in Fig. 1 in another embodiment.
Specific implementation mode
The exemplary audio digitization system for embodying the present invention is shown in Fig. 1.The digitization system 10 is for the company of scanning
Continue mobile strip recording medium 11, and the analog sound information being recorded in the recording medium 11 is digitized.Fig. 2 shows
The example for the recording medium 11 that can be used in combination with system shown in Fig. 1.In this example, it is film 11a.Although
In preferred embodiment, it is illustrated so that cinefilm digitizes as an example, thus recording medium 11 is to record to have on film 11a
The cinefilm of one or more tracks, however, it should be understood that the other embodiment of the present invention is equally applicable to and other
The analog encoding recording medium (e.g., open reel tape, drum-type gramophone and single etc.) for needing transmission mechanism of form
It is used together.
Film 11a includes one or more analog sound tracks 14 along one or two edge, and the analog sound track is to film
Frame sequence 13a, 13b provide monophonic or dual-channel audio information.According to recording technology used, track 14 can be divided into magnetic sound
Rail or optical sound track.Synchronization track 12 (or also referred to as benchmark track) is may also set up, synchronization track generally includes multiple holes.
Each hole or one group of Kong Keyu each frame 13a, 13b are associated.Benchmark track 12 is commonly provided for passing in film moving process
It send and stable base film 11a.It also is used as the canonical reference that certain camera systems measure frame sign.
Now referring again to Fig. 1, recording medium 11 is carried by Transmission system 15, and Transmission system 15 makes recording medium 11 with basic
Constant speed moves through reading head 16, to read the analog sound information of storage.In an illustrated embodiment, reading head 16
Associated scan position, recording medium 11 are scanned when across the position.In this example, reading head 16 is one
Optical pickup.The light source 17 of the optical sound track of irradiation recording medium 11 is equipped on the side of recording medium 11.It is situated between in record
The other side of matter 11 is equipped with reading head 16, which receives the light transmitted via recording medium 11, and generates representative
Via the analog output signal for the light that recording medium 11 is transmitted.Then, analog output signal is sent to analog-digital converter (ADC)
18 are converted into digital form.Although shown in Fig. 1 being a kind of system of optical storage and reading track, it is to be understood, however, that
, it is magnetic track that the present invention, which is also easy in track, and reading head is to be used in magnetic other systems.In some embodiments
In, recording medium 11 may include the track of (e.g., optics and magnetism) in a variety of forms coding, and the system may include with each
The corresponding reading head of track.
According to the present invention, analog-digital converter 18 is configured to the transmission rate determination sensed based on recording medium 11
Sample rate samples the simulation output of reading head 16.The sample rate differs very little, and changeable with digitized target sample rate
The sample rate compensates transmission rate deviation of the recording medium 11 relative to reading head 16.
The transmission rate of recording medium 11 can determine by various modes.In one embodiment, the biography of recording medium 11
Defeated rate can be based at least one rotary part 19 of the transmission mechanism 15 of bearing recording medium 11 speed or speed come
It determines.More specifically, system 10 can monitor rotation or the prison of the rotary part 19 of the transmission mechanism 15 of bearing recording medium 11
Survey the rotating element (not shown) for the rotary part 19 for being rotationally attached to transmission mechanism 15.In some cases, the system
The linear movement of the element (not shown) by the rotary part movement of Transmission system can be monitored.In the especially preferred embodiments,
Rotary part 19 is that recording medium 11 passes through accurate roller thereon.The roller can processing and installation on bearing, to ensure it very
It is close to round (or being accurate to the machining tolerance actually allowed), and can be with the drive manner as close possible to concentric circularity
It is installed on bearing.In addition, being equipped with multiple reading heads in the diameter opposite side of roller 19, the setting of these reading heads can eliminate roller
19 influence caused by due to rotational concentricity deficiency.
Fig. 3 shows the more details of embodiment shown in Fig. 1.In this embodiment, transmission mechanism 15 includes rotatable
Ground is connected to the encoder 20 on the roller 19 of transmission mechanism 15.Encoder 20 is configured to generate 20 rotation position of instruction encoder
Output signal.For example, each turnover that encoder 20 is configured as roller 19 generates arbitrary an appropriate number of pulse.In a reality
It applies in example, produces 512 subpulses, and in other embodiments, produce greater number pulse, e.g., 1000 times.Encoder 20
Output signal received and analyzed by speed estimator 21.The speed estimator 21 have high frequency clock (e.g., 150MHz) and
Record the quantity of the pulse received from encoder 20.Thus speed estimator 21 can calculate rotation of the roller 19 in transmission process
Rotary speed fluctuates.If it is determined that it is expected that between rotating speed that then speed estimator 21 will generate a frequency adjustment letter there are deviation
Number, which then generates the modulator clock signal of ADC converters 18 together with clock base frequency.
Those skilled in the art are it should be understood that the sample rate for digitized simulation audio signal ordinarily is about
50kHz so that can capture and the sound in frequency band similar in mankind's hearing frequency band.In this example, the mesh of ADC converters 18
Mark sample rate is 48kHz.In this example, ADC converters 18 are using increment accumulation modulator (Delta Sigma
modulator).Those skilled in the art it should be understood that increment accumulation modulator have single-bit analog-digital converter, and
Over-sampling can be carried out to analog signal to be higher by target sampling rate (e.g., 48kHz) many frequencies.Increment accumulation modulator is adopted
The bit-depth needed for signal digitlization is provided with over-sampling.In some embodiments, it can equalize and be modulated from increment accumulation
The output signal (with converter sampling rate as described below) of device, and combination producing one and traditional analog-digital converter are with target frequency
The comparable signal of signal of rate (e.g., 48kHz) sampling.
ADC converters 18 have modulator clock signal, implement control in each continuous sampling of ADC converters.At this
In example, modulator clock frequency is usually 12.288MHz, still, in order to ensure keeping institute under different transmission speed/interference
Sample frequency is needed, modulator clock frequency can be changed according to the sample frequency needed for output voice signal.In this example, increment
Accumulation analog-to-digital converter is run in a manner of being equal to traditional 8 bit 48kHz analog-digital converters.In other embodiments, it can adopt
With higher or lower bit-depth or sample rate, e.g., 24 bit 9696kHz outputs.In a preferred embodiment of the invention, it is based on
The output adjustment modulator clock frequency (raise or lower using centre frequency as standard) of speed estimator 21, is being transmitted with compensation
The velocity deviation sensed during recording medium 11.Preferably, velocity deviation is within the scope of 2.048~15.36HMz, but
Higher or lower speed can be used.When the instantaneous transmission speed of recording medium 11 is less than desired value, the rotary frequency of roller 19 is reduced
Rate.Encoder 20 can then detect this variation, and speed estimator 21 will turn down the frequency of modulator clock signal.With
Increase ADC converters 18 sampling time.On the contrary, if the fluctuation of transmission speed is more than desired value, increase modulator
Clock frequency and the actual sample rate for correspondingly increasing ADC converters 18, e.g., according to the above preferred modulator clock
Frequency:Between 8~60kHz.
For conceptive, it is contemplated that for the simple sinusoidal sound wave that can be used as the playback of fixed frequency tone.In order to
The tone is sampled, sample can be taken in the every secondary wave crest and trough of analog signal, wherein wave crest and trough on waveform 30 with
Ellipse representation.Since transmission speed fluctuates in replayed section, the analogue audio frequency output that audio reader 16 is read
Signal is not a complete sine signals, and the time domain of the waveform of a portion is compressed, and the time domain broadening in another portion.When adopting
(when the ideal position of waveform wave crest and trough samples) is sampled with fixed rate, wave crest and trough can be ignored.However, in this hair
In bright embodiment, the sample rate of digitaling analoging signal is may be adjusted for, for example, by adjusting the clock letter of control sample rate
Number, so that it is matched with the time domain interference in waveform.This makes the sample taken at waveform wave crest and wave crest more consistent, and
And the sample and trough taken in waveform trough are more consistent (ellipse as shown in waveform 32).Although ADC converters is defeated
It is to be derived under variable sampling rate, but bit stream is to be exported (in the examples described above, with fixed target bit rate to go out bit stream
Target bit rate is 48kHz).
The output bit stream 32 of ADC converters is sent to audio buffer 34 with scheduled bit rate.But, it may be necessary to it adjusts
Whole output bit stream makes it be consistent with required downstream bit stream.This can be realized by sampling rate converter 36.For example, sampling
Rate converter receives reference frequency from the component (e.g., roller 38) of Transmission system.The reference frequency indicate recording medium 11 relative to
The transmission rate of output signal demand.For example, if Digital output signal indicates transmission 24 frames (fps) audio per second, and it is real
Border transmission rate is only 12fps, then buffer storage 34 will accumulate twice sample number generated needed for audio output signal.It adopts
Sample rate converter 36 corrects unmatched output signal.
In another example, if Digital output signal expression transmission 24 frames (fps) audio per second, and actual transmissions
Rate is 30fps, then buffer storage 34 needs the sample number accumulated far below the sample number generated needed for audio output signal.
Such case waveform 31 indicates, wherein can directly be generated by ADC converters 18 with the sampled point that ellipse indicates.However, this
Show analog signal undersampling (be primarily due to each second digitized frame number excessive).In this case, sample rate turns
Data flow of the output of parallel operation 36 containing 6 data points with square indicia, rather than the sampled value containing 5 with ellipse label
Data flow.Sample rate transformation mechanism can be used any suitable technology well known by persons skilled in the art and carry out.
The second feedback mechanism also can be used to control the accumulation of digitized audio in buffer storage 34.It should be understood that
It is that buffer storage 34 must can be fed containing enough without the data of spilling to sampling rate converter.This can pass through
It monitors the use of buffer and estimator 21 of accordingly regulating the speed above and below is generated control signals to by PID controller 37
It exports to be controlled.PID controller 37 is usually adjusted with lower frequency and (e.g., is less than audible frequency), therefore, Bu Huiying
Ring the quality of output audio.
Fig. 4 shows the second embodiment of system shown in Fig. 1.Its common trait is consistent with reference number, no longer superfluous herein
It states.System shown in system and Fig. 3 in the present embodiment is not the difference is that the system in the present embodiment includes sample rate
Converter 36.This is because the system in the present embodiment allows ADC converters 18 in the frequency model compared to earlier examples bigger
Enclose interior change modulator clock signal.
Allow ADC converters 18 to change frequency in a wider context, flutter and mesh in correction can be handled
The bigger frequency departure occurred within the scope of sample rate is marked, for example, higher can also be used between 8~60kHz in target sampling rate
Or lower sample rate.
In addition, transmission mechanism 15 includes the encoder 20 being rotationally attached on the roller 19 of transmission mechanism 15.Encoder
20 are configured to generate the output signal of 20 rotation position of instruction encoder.The output signal of encoder 20 is by speed estimator 21
It receives and analyzes.Speed estimator 21 records the step-by-step counting received from encoder 20.As described in above-described embodiment, it can adopt
With any suitable number of encoder pulse, but every turn pulse and be considered to be suitable for about 1000 times.Speed estimator 21 can be by
This calculates rotary speed fluctuation of the roller 19 in transmission process.If it is determined that it is expected between rotating speed there are deviation, then speed
Estimator 21 will generate a frequency adjusted signal, which then generates the modulation of ADC converters 18 together with clock base frequency
Device clock signal.Modulator clock signal implements control in each continuous sampling of ADC converters.Based on speed estimator 21
Output adjustment modulator clock frequency (is raised or is lowered using centre frequency as standard), to compensate in 11 process of transmission log medium
In the velocity deviation that senses.The output bit stream 32 of ADC converters is sent to audio buffer 34 with scheduled bit rate.At this
In example, Digital output signal can directly be read from buffer storage 34, without resampling.It should be understood that this
Embodiment can be target sampling rate identical with embodiment shown in Fig. 3 (e.g., between 8~60kHz or 96kHz or more)
It is realized under bit-depth (e.g., 8 bits, 24 bits or other required bit-depths).
The second feedback mechanism also can be used to control the accumulation of digitized audio in buffer storage 34.It should be understood that
It is that buffer storage 34 must contain enough without the data of spilling, can be with the sample rate output data of correction.This can
By monitoring the use of buffer and generating control signals to estimator of accordingly regulating the speed above and below by PID controller 37
21 output is controlled.PID controller 37 is usually adjusted with lower frequency and (e.g., is less than audible frequency), therefore, no
It can influence the quality of output audio.
It should be understood that the invention for disclosing and limiting in this specification may extend to refer to herein or in attached drawing or root
According to the alternative combination of whole of this paper or the obvious two or more independent features of attached drawing.All these different combination structures
At each alternative aspect of the present invention.
Claims (29)
1. a kind of track method for digitizing for that will be carried in strip recording medium, the method includes:
Recording medium containing track is conveyed through reader, its sequence is made to read track;
The track is read by reader, to generate analog output signal;
Sense the transmission rate of the recording medium;And
The analog output signal is sampled with the sample rate determined based on the transmission rate sensed so that the simulation
Output signal digitizes.
2. according to the method described in claim 1, wherein, when the sample rate can be based on modulator with clock modulation frequency
Clock signal determines.
3. a kind of track method for digitizing for that will be carried in strip recording medium, the method includes:
Recording medium containing track is conveyed through reader, its sequence is made to read track;
The track is read by reader, to generate analog output signal;
Sense the transmission rate of the recording medium;
The modulator clock signal with clock modulation frequency is generated based on the transmission rate sensed;And
The modulator clock signal is applied to analog-digital converter so that the analog output signal digitlization.
4. the method according to any one of preceding claims, wherein sense the transmission rate of the recording medium
Step, including:
Determine the rotational frequency or speed of at least one rotary part for the transmission mechanism for carrying the recording medium.
5. the method according to any one of preceding claims, wherein sense the transmission rate of the recording medium
Step may include any one or more in following steps:
Monitoring carries the rotation of at least one rotary part of the transmission mechanism of the recording medium;
Monitor the rotating element for being rotationally attached at least one rotary part of the transmission mechanism;And
Monitor the linear movement of the element moved by least one rotary part.
6. the method according to any one of preceding claims, wherein sense the transmission rate of the recording medium
Step includes:
One or more output signals are received from the encoder for the rotary part for being rotationally attached to the transmission mechanism.
7. according to the method described in claim 6, wherein, the encoder is synchronous with the rotary part of the transmission mechanism to be revolved
Turn.
8. the method described according to claim 6 or 7, wherein the rotary part each rotation of the transmission mechanism, the coding
Device generates 1000 output signals.
9. according to any one of claim 6 to 8 or the multinomial method, wherein the method further includes:Based on from institute
It states the output signal that encoder receives and adjusts the clock modulation frequency.
10. method as claimed in any of claims 2 to 9, wherein the clock modulation frequency is based on adjustment frequency
It is determined with clock base frequency.
11. according to the method described in claim 10, wherein, the clock base frequency is between 2.048~15.36MHz.
12. the method according to any one of preceding claims, wherein the sample rate is between 8~60kHz.
13. the method according to any one of claim 4 to 12, wherein the rotary part of the transmission mechanism can wrap
It includes any one or more in roller, gear, sprocket wheel, driving wheel, mandrel, axis and spool etc..
14. the method according to any one of claim 4 to 12, wherein the rotary part is situated between with the record
Matter rotates consistent high precision roller.
15. the method according to any one of preceding claims, wherein the step of reading the track may include following
One or more of step:
Receive the optical signal for indicating pumped FIR laser track;Or
Sense magnetic encoded tracks.
16. the method according to any one of preceding claims, further includes:
The digitized simulation output signal is transmitted to buffer storage;
Monitor the state of the buffer storage;And
State based on the buffer storage adjusts clock modulation frequency.
17. the method according to any one of preceding claims, further includes:
Based on one or more of following reference frequency for determining digitized simulation output signal:
Carry the measurement speed or speed of at least one rotary part of the transmission mechanism of the recording medium;And
The input signal for driving at least one rotary part of the transmission mechanism to rotate.
18. according to the method for claim 17, wherein the reference frequency can be final with the Digital output signal
Bit rate output is associated.
19. the method according to any one of claim 16 to 18, wherein the method further includes:
Access the digitized simulation output signal being stored in the buffer memory;And
Based on the reference signal and the digitized simulation output signal being stored in the buffer storage, correction is generated
Digitized simulation output signal.
20. a kind of digitized audio frequency system, including:
Reader is configured to read from the audio-frequency information of storage on the recording medium, and generates analog output signal;
Transmission mechanism is configured to the recording medium for making carrying need the digitized audio-frequency information and passes through the reader;With
And
Analog-digital converter is configured to sample the analog output signal of reader with sample rate, wherein sample rate depends on described
The transmission rate of recording medium.
21. a kind of digitized audio frequency system, including:
Reader is configured to read from the audio-frequency information of storage on the recording medium, and generates analog output signal;
Transmission mechanism is configured to the recording medium for making carrying need the digitized audio-frequency information and passes through reader;And
Clock signal generators are configured to generate modulator clock signal;Wherein, analog-digital converter (ADC) is configured to based on tune
Device clock signal processed samples the analog output signal of the reader.
22. the digitized audio frequency system according to claim 20 or 21, further includes:Sensing system is arranged to described in sensing
The transmission rate of recording medium.
23. the digitized audio frequency system according to any one of claim 20 to 22, wherein the sensing system is in phase
The transmission rate of the recording medium is sensed adjacent to the position of the reader.
24. the digitized audio frequency system according to any one of claim 20 to 23, wherein the sensing system can match
The reference clock signal of clock signal can be directly used as by being set to output, or is generated by clock signal generators and supplied the modulus
The clock signal that converter uses.
25. the digitized audio frequency system according to any one of claim 20 to 24, wherein the sensing system can wrap
Include the encoder for the component for being rotationally attached to the transmission mechanism, wherein described in the component of the transmission mechanism and transmission
Recording medium passes through the reader synchronous rotary.
26. according to the digitized audio frequency system described in claim 25, wherein the encoder can be connected to roller, gear, chain
It is any one or more in wheel, driving wheel, mandrel, axis and spool etc.;Rotating element is rotationally attached to times among the above
Meaning one.
27. the digitized audio frequency system according to any one of claim 20 to 26, wherein the reader may include
It is any one or more in following:
Optical pickup is configured to read from pumped FIR laser track;Or
Magnetic reader is configured to read from magnetic encoded tracks.
28. a kind of glue including the digitized audio frequency system described in any one of claim 20 to 27 turns magnetomechanical, film glue
Piece scanner and video digitizer etc..
29. the digitized audio frequency system configuration described in any one of claim 20 to 27 is required at perform claim in 1 to 19
Method described in any one.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2017901187A AU2017901187A0 (en) | 2017-03-31 | Audio digitization | |
| AU2017901187 | 2017-03-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108694961A true CN108694961A (en) | 2018-10-23 |
Family
ID=61868191
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810283497.0A Pending CN108694961A (en) | 2017-03-31 | 2018-04-02 | Digitized audio frequency |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US10388306B2 (en) |
| EP (1) | EP3382705A1 (en) |
| JP (1) | JP2018190482A (en) |
| CN (1) | CN108694961A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110176262A (en) * | 2019-04-23 | 2019-08-27 | 上海协言科学技术服务有限公司 | The method that a kind of pair of wire recording carries out digital conversion |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20220189444A1 (en) * | 2020-12-14 | 2022-06-16 | Slate Digital France | Note stabilization and transition boost in automatic pitch correction system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5481810A (en) * | 1977-12-07 | 1979-06-29 | Kokusai Gijutsu Kaihatsu Kk | Recorder*reproducer |
| JPH07107759B2 (en) * | 1983-09-14 | 1995-11-15 | 株式会社日立製作所 | Rotating head PCM recorder |
| JP2000195172A (en) * | 1998-12-24 | 2000-07-14 | Sony Corp | Data recording and/or reproducing device |
| US7974035B2 (en) * | 2006-06-29 | 2011-07-05 | Broadcom Corporation | Timing recovery optimization using disk clock |
-
2018
- 2018-03-28 JP JP2018061254A patent/JP2018190482A/en active Pending
- 2018-03-28 EP EP18164719.9A patent/EP3382705A1/en not_active Withdrawn
- 2018-03-29 US US15/940,131 patent/US10388306B2/en active Active
- 2018-04-02 CN CN201810283497.0A patent/CN108694961A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110176262A (en) * | 2019-04-23 | 2019-08-27 | 上海协言科学技术服务有限公司 | The method that a kind of pair of wire recording carries out digital conversion |
| CN110176262B (en) * | 2019-04-23 | 2023-12-26 | 上海协言科学技术服务有限公司 | Method for digital conversion of steel wire recording |
Also Published As
| Publication number | Publication date |
|---|---|
| US20180294002A1 (en) | 2018-10-11 |
| EP3382705A1 (en) | 2018-10-03 |
| JP2018190482A (en) | 2018-11-29 |
| US10388306B2 (en) | 2019-08-20 |
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